Joe Friel's Blog is for the serious endurance athlete who wants to stay current on the science and art of training for sport. Here you will find Joe Friel's thoughts and ideas before they are published anywhere else. You may also visit www.TrainingBible.com for more detailed and free content. Joe's training plans are available at www.TrainingPeaks.com.

10/02/2013

Aging: High-Intensity Training

In
my previous posts I’ve been making the point that the physical aspects of
performance that science tells us are most likely to need our attention as we
age are aerobic capacity (VO2max), muscle mass and body weight. I’ve already
discussed the last one here. Let’s move on to how your
aerobic capacity and muscle mass may be maintained or even increased. I’ll
discuss the first one in this post and then tell you what I’ve learned about
muscle mass later on. I’ll also get into what can be done to avoid age-related training
interruptions due to injury since aerobic capacity training and muscle
development may increase your risk.

The
research on aging in experienced endurance athletes tells us that in order to
reduce the decline in aerobic capacity with advancing age, training must be
intense. That typically means just below, at or above the lactate threshold
(anaerobic threshold, functional threshold, etc) based on heart rate, pace, speed, power or perceived exertion. For experienced endurance athletes, an exercise
regimen based solely on long, slow distance will do little to improve or even
maintain your aerobic fitness status over the years.

Of
course, you simply may not be able to improve it, especially if you’ve been
training intensely for many years. Even with such focused training there is
still the age-related performance decay that research has repeatedly shown us
is inevitable. Your current age and history of exercise consistency has a lot
to do with how great the gains may be in the future. If your training has been
inconsistent and you are in your 50s you’re more physiologically capable of significantly
reversing the downward performance spiral through training than if you are in
your 70s. That doesn’t mean a 70-year-old can’t make performance gains after a
few years of slacking off. It’s just somewhat harder to accomplish due to
physiological changes that occur with advancing age such as reduced hormone
production.

There
is also the matter of genetics. Some people apparently won the genetic lottery.
They are endowed with a great capacity for hard workouts with little risk of
breakdown. They can do high-intensity training and experience a quick and
positive response. Others of the same age can do the same workouts over the
same time and see little or no performance change. Life just isn’t fair.

There’s
little doubt that intense training is risky. As workouts become more
challenging, the chances of injury, illness and overtraining increase. Intense
training needs to be modulated in regards to your current level of fitness and personal
age-related limits. Those limits may have become magnified by the absence of
high-intensity training in recent years. If that’s the case, you need to be
extra conservative with training changes as you ease into what I’m going to
propose below.

If
high-intensity training is something you haven’t done for a long time or never
before then there are several things you must consider. These include the type
of hard workouts, the frequency of hard workouts, short-term recovery from hard
workouts and nutrition relative to hard workouts. I’ll cover these last few
points in future posts. But for now let’s look at high-intensity training for
aerobic capacity.

The
most effective and efficient use of your time and energy to increase training
intensity is by doing some type of interval training.

When
doing intervals the absolute intensity, duration of the repetitions, number of
repetitions and the durations of recoveries between them must be only slightly
more challenging than your estimated current capacity for physical stress. Because this type of
workout can be quite stressful, an interval session should be preceded by a
gradually progressing warm-up and should end when a reasonable workout goal is
attained, when it is apparent that high-end performance is declining or when
effort feels unusually high for the output (pace, speed, power).

If
you have been diagnosed with coronary heart disease, have concerns about your
heart health or be on statins or other medications that alter heart rate then
you should consult with your doctor before starting an interval-training
program. Fortunately, the risk of heart attack among apparently healthy
athletes as they age is quite low (Mengelkoch).

If
you’ve previously done intervals throughout your sport career but have had a
gap in recent years then you know how to get started again. But if long, slow
distance training has been your only training method then you may need some
guidelines for interval training. That’s what follows.

A
typical first session for someone who has not done interval training recently
may be something such as…

a. Warm-up
10-30 minutes gradually ratcheting intensity up to zone 3. It’s common for
older athletes to need more warm-up than young athletes. Warm-up may also vary
by sport. For example, it is typically longer for cycling than for running.
Swimming generally falls between these two.

b. Do 3 x
3-minute reps with each rep in zone 4 and 3 minutes of recovery in zone 1
between them. Rep intensity may be based on heart rate, pace, speed, power
or perceived exertion. Some of these are better than others depending on the
sport. Heart rate-based intensity is perhaps the worst way to gauge how hard to
work with intervals as heart rate rises slowly. It may take several minutes to
achieve zone 4 during which time you are left guessing how hard to work. Most
athletes err on the side of starting intervals too fast to force heart rate up
and then slow down later as zone 4 heart rate is finally achieved. This is just
the opposite of what should be done which is to finish each rep with a slightly
higher intensity than it was started.

c. Cool
down with several minutes of easy exercise in zone 1. As with the warm-up,
the duration of the cool down depends on the sport with cycling typically long
and running relatively short.

At
first such a workout may only be done once in a week, but over time the number
of such weekly sessions may be increased to two. It’s uncommon for senior
athletes to be capable of doing more than two in a week. I’ve coached some who
can but they are rare and more likely in their 50s rather than their 70s.

An
indication of improving fitness is that the speed or power of the reps
increases relative to heart rate. To determine this you can divide the combined,
average speed or Normalized Power for the reps by the combined, average heart rates for
the reps. As this ratio increases your fitness is improving. TrainingPeaks calls this “Efficiency Factor (EF).”

As
the EF for your interval sessions rises, increase the number of reps. As the
longer-rep sessions become tolerable begin to gradually increase the duration
of the reps. When you can easily manage about 20 minutes total combined rep
time (such 4 reps of 5 minutes each at zone 4) with recoveries about 1/4th
as long time-wise as the preceding interval (75 seconds for a 5-minute rep) in a single workout then you are
ready to move onto slightly more intense intervals. Start again
with 3 x 3 minutes with 3-minute recoveries, only this time just above lactate threshold.

Over
several weeks as the intensity moves up to zone 5b heart rate or pace (see my
Cyclist’sTraining Bible
or Triathlete’sTraining Bible for details on zones) or zone 5 power (see
myPower Meter Handbook), restrict the rep durations to 2-4 minutes with recovery durations
of the same length. And restrict the total combined interval time to no more
than about 15 minutes. At this intensity most older athletes generally should
not do more than one such session per week while perhaps continuing to also do
one of the zone 4 sessions in a week. The time gap between such weekly sessions
should be at least two days, three is usually better. Some athletes will not be
able to handle two interval sessions in a week. That’s not unusual. If unsure,
do only one per week.

Once
you become fully accustomed to doing intervals you can modify the components of
the session by changing such elements as the duration progression of the reps,
terrain for the reps, number of reps, total combined time of the reps and
durations of the recoveries. You can also combine various types of interval and
steady-state sessions into a single workout. But be patient with such advances.
Don’t rush into them or you greatly increase your risk of injury. Patience is
the key to training consistency as you get older. If in doubt, leave it out.

All
of this brings us to the peripheral training adjustments that are usually
necessary for older athletes to avoid injury. I’ll get to that after discussing aging and muscle mass in my
next post.

Would this the same line of thinking apply to preparing an athlete to race in high altitude (when they live and train at sea level)? Meaning - high intensity interval training may be used as a way to help better prepare aerobic conditioning for what an athlete may experience (decrease in VO2 max) when traveling to race at high-altitude?

Scott Matney--Thanks for your comment. That's per week, especially if doing anaerobic endurance (VO2max) intervals. Also has to do with how many total reps a person can tolerate in a week. They could be spread out over 3 sports. And some sports are more challenging than others in terms of risk and recovery needs. Running is at the top of that list. Someone who is 50 can probably handle more than someone who is 70. And, of course, there are always remarkable people of all ages who can do more than most. It comes down to who we're talking about. I was giving general guidelines for a mid-curve audience.